The prior art discloses many permutations of automobile passive seat belt arrangements that basically comprise a lap belt and a shoulder harness for restraining a seat occupant in a vehicle seating position. In nearly all of the disclosed passive seat belt arrangements, the seat occupant restraining position of the lap belt and shoulder harness is controlled by or related to the position of the vehicle door. That is, when the door is moved from an opened to a closed position, the lap belt and shoulder harness automatically embrace or encircle the seat occupant. When the door is moved from the closed to an opened position, the lap belt and shoulder harness are displaced from the seating position to facilitate egress or ingress from the vehicle passenger compartment. The term "passive," as used in the expression "passive seat belt system," thus means that the seat occupant is not required to do anything but close the car door to become belted in the seat or to open the door to become unbelted.
U.S. Pat. No. 3,976,305 issued Aug. 24, 1976 to Walter Fieni for a "Safety Belt Assembly for a Motor Vehicle" discloses a passive seat belt system that exemplifies one form such a system may take. The disclosed seat belt system comprises a shoulder or torso belt and a transverse or lap belt, generally formed by a single continuous belt of fixed length that is anchored to the vehicle door at upper and lower anchorage points. A belt positioning strap extending from an inboard retractor mechanism is fixedly coupled to the belt intermediate its ends. In door closed position, the portions of the belt between the fixed point at which the strap is coupled to the belt and the lower anchorage point and the fixed point and the upper anchorage point form a lap belt segment and a torso belt segment, respectively.
One problem with the foregoing system is that the belt and control strap must lie in proximity to the seat when in passenger restraining position, and preferably should be raised in door opened position to permit easy ingress/egress to the seating position. Many complicated systems have been proposed for raising the belt system. The aforementioned U.S. Pat. No. 3,976,305 discloses a pnuematically or hydraulically operable variable length arm for lengthening the belt system positioning strap that is responsive to movement of the door for freeing the occupant from the seat upon opening of the door.
Other known systems involve the use of pulleys and cables to move belt positioning devices slidable in tracks and guides in vehicle doors and roof rails.
It is an object of the present invention to accomplish the desired belt raising and lowering operation with a simple and positive improvement to the belt system.